Troubleshooting for low fan speeds – CTRLFAN 2

Diagnostic code 751

Diagnostic code 751 occurs when the CTRLFAN 2 fan is not operating to specifications.

Symptoms

Code Symptoms XPR® models XPR action Code cancels with...
751 The fan speed for CTRLFAN 2 is less than the minimum acceptable Revolutions Per Minute (RPM) value. XPR170®, XPR300® None
  • Set process
  • Remote on-off

Corrective action

  1. Use the Fan diagnostic codes diagram to identify the location of CTRLFAN 2 in the plasma power supply.
  2. Make sure that the following fan connections are good, and tighten loose connections if found:
    • The fan connector
    • The wiring to J8 on the fan power distribution Printed Circuit Board (PCB)
    • The wiring to J7 on the control PCB
  3. Examine the 48 VDC power source output.
  4. If the power output is not correct, replace the 48 VDC power source.
  5. If you do not find any loose connections and the 48 VDC power source is good, replace the fan.